Networks, such as the wired/wireless Internet and intranets, have already been widely used as popularized communication means. The World Wide Web (WWW) and means, such as e-mail and messaging, that allow members of society to share information or obtain knowledge based on such networks have been actively utilized.
Recently, Internet service for enabling not only the use of a network simply as communication means but also the construction of an online social network using the network has been actively provided. The term “social network” refers to a virtual network based on individuals who have made acquaintance through social life. The term “acquaintance” refers to the range of persons who build trust therebetween to some degree as a result of sharing information, experience, ideas, and a sense of belonging to a community to some degree. Based on the aspects of general social life, such acquaintances are established by knowing each other through the extension of existing acquaintances, through blood relations, school relationships or neighborhood relationships, through belonging to specific organizations, or through the performance of collective work in a company or team.
Recently, due to the development and popularization of networks such as the Internet; the online establishment and management of such acquaintances has become possible. Various types of service technologies for supporting the active online construction of such social networks between users, organizing constructed social network into databases, enabling users to search for persons possessing desired capability and careers, or allowing users to establish online social network relationships with new acquaintances and to further extend their social networks, based on the databases, and enabling users to share various files or information have been proposed.
In the technologies for constructing and managing social networks online, the principal objectives of technical development in a corresponding field are to guarantee the trust of mutual human relationships in view of the characteristic of a network, such as the Internet, in which a number of anonymous persons can gain access to the network to construct social networks in wide ranges, and to minimize inconvenient procedures necessary to receive service.
Systems for constructing and managing social networks online, which are currently widely used, include two types: those which provide access to web servers of associations of like-minded persons, communities or the like and enable receipt of services, and those in which terminals are provided with application programs and receive service while communicating with servers.
Such a prior art system for constructing and managing a social network online is generally initiated in such a way that a user requests another person, who accesses a network to establish an online relationship via a means, such as e-mail, messaging, or a pop-up message, and the person, who receives the request, responds to the request. The 1:1 relationship between the two users, which is established as described above, is integrated into an online social network in which each user has established separate 1:1 relationships with other users. Due to the integration with the online social network it is possible to search for a desired person (for example, an alumnus or a person having a specific occupation) from among users who have made acquaintance directly with a user (first order acquaintance relationships) and among users who have first order acquaintance relationships with acquaintances and other users who have made acquaintance with the other users (n-th order acquaintance relationships), and to request the introduction of a found person or the establishment of a new acquaintance relationship therethrough.
FIG. 1 illustrates a prior art social network search system 100. The illustrated social network search system 100 is constructed to include a DataBase (DB) 10 and a search server 20. The DB 10 includes a user DB 12 and a relationship information DB 14. The social network search system 100 accesses a plurality of user trials 310, 320, 330 and 340 via networks 200, including the wired/wireless Internet and/or intranets. Although only four user terminals are illustrated for the purpose of convenience, the user terminals may be various fixed or mobile terminals, such as laptops, desktops, Personal Digital Assistants (PDAs), and Personal Communications Service (PCS) terminals.
In a user registration process, step A, at which a first user registers with the social network search system 100 via his or her terminal 310, is performed, and step B, at which a fourth user registers with the social network search system 100 via his or her terminal 340, is separately performed. In this registration process, the ID, password and personal information (occupation, gender, age, place of residence, company name, school and hobby) of each user may be input) and the user's information is converted into a predetermined data structure and stored (step C) and managed in the user DB 12. At the time of each user subscribing to and registering with service (steps A and B), the social network search system 100 may cause a specific application program, allowing users to easily use various functions, provided by the system, in conjunction with the search system to be downloaded to and executed on the respective user terminals.
FIG. 2 illustrates the step of establishing a corresponding relationship between users (first order acquaintance relationship) in the prior art social network search system 100. Step D, at which, in order to establish a first order online acquaintance relationship between the users, the first user sends an invitation message to the second user's terminal 330 via his or her terminal 330, and the fourth user checks the invitation message and sends an acceptance message, can be performed. The invitation and acceptance messages may be in various forms, and the social network search system 100 becomes aware of the performance of the invitation and acceptance steps and records the establishment of a corresponding relationship between the two users in the relationship information DB 14 using a predetermined data structure (step E). In this case, the fourth user may be an unregistered user, in which case a step of inducing the user to register with the system through data transmission to and reception from the social network system 100 at the time of sending the approval message with respect to the invitation may be performed together with the other steps.
FIG. 3 illustrates the step of searching a social network in the prior art social network search system 100. When a request for specific condition setting and social network search is received via the first user's terminal 310 (step H), the search server 20 of the system 100 reads data recorded in the user DB 12 and the relationship information DB 14, converts the data, loads the converted data into a memory module provided in the search server 20 (step D), and conducts a search using the loaded data.
FIG. 4 illustrates the data structure of the user DB 12. As illustrate in the user DB 12, user information, such as the name, age, occupation and gender of each user, is stored in association with each user ID (Userid1, 2, 3, . . . ). FIG. 5 illustrates the data structure of the relationship information DB 14. As illustrated, in the relationship information DB 14, user IDs having a corresponding relationship (first order acquaintance relationship) are stored with a 1:1 relationship.
FIG. 6 is a schematic diagram illustrating an online social network search space. In a vital social network search space, respective users who registered with a system correspond to respective nodes a, b, c, d, . . . . According to corresponding relationships between users, links or edges are formed between the nodes of the search space. The search space formed as described above may be represented using a graph data structure. In this search space, start node ‘a’ from which a search starts is defined. In the illustrated example, users within second order acquaintance relationships around the search start node ‘a’ are illustrated. When the user requests a search for a user who meets a specific condition (for example, a patent attorney) within second order acquaintance relationships, the search is performed within the illustrated range.
FIG. 7 illustrates the result of a shortest distance search within the online social network search space. This is a case where the user requested a search for the shortest distance between node ‘a’ corresponding to the user and node ‘p’ corresponding to another user (a distance having a minimal number of intermediate nodes), with the result that the shortest distance ‘a-b-e-j-p’ within the social network search space is found and is displayed to the user.
However, in the prior art social network management system, it is possible to establish only 1:1 acquaintance relationships, but it is impossible to establish various relational levels (differences in the extent of the relationship, differences in trust depending on counterpart, the extents of acquaintance relationships, and the like). Accordingly, it is impossible to provide differentiated information according to relational level. Rather, in the case of establishing relationships with untrustworthy counterparts online, there is concern about the leakage of information, so that cases of reluctance to establish a wide online social network have occurred.
Furthermore, in the case of a user who is active and establishes a large network requests, inquiries and favors are concentrated on the user and a large amount of time is consumed, so that the corresponding user escapes from the online social network so as to avoid the above problem, therefore a problem occurs in that the already established online social network around the user collapses.